This weather pattern of blazingly hot followed by wet and cool is perfect for many pests and diseases in the landscape. During our pruning work, we've noticed the following:
on pieris, boxwood, cotoneaster, azalea and small leaf rhododendron - You will see a tell-tale yellowing of broadleaf evergreen foliage from a distance sometimes. As you draw nearer, you see that the leaves are covered with yellow pin pricks. This is the sucking action of the lacebug, quite literally drawing the sap from the leaves. Eggs are laid on the back side and look like small black dots.
We can spray foliage with a Neem oil product to smother this pest and its eggs. One caution is to avoid using this product when temperatures are above 80 degrees so it does not burn foliage. A good follow-up plan is to test and amend soil this fall. A soil with Phosphorus in balance nurtures shrubs that are less attractive to insect pests.
Fall Webworm emerges in July, making its web-like cocoon nest at the end of tree branches in the rose family (apple, crabapple, cherry) but also favors birch, hickory and lilac. The easiest remedy is to reach up and remove the cocoon and its larvae from the site. Sometimes this has to be pruned out. Spraying with Insecticidal Soap also helps, provided we can reach the area with our spray equipment. Only the nest itself needs to be sprayed
Fall webworm in Cherry Tree
Magnolia Scale is again prevalent this season. Look for white dots on the magnolia branches. You may also see black soot-like mold on the leaves of the tree, on plants growing beneath it, or on nearby hardscapes. This so-called sooty mold is a byproduct of the scale pest. Unfortunately, sooty mold also attracts bees and wasps that collect its honeydew. So it can be downright dangerous to stand or work near a magnolia tree at this time of year.
We use a multi-prong approach to these issues. First of all, keep your magnolia pruned and open to allow good air circulation. Scale will congregate where air does not flow well. If your tree already shows extensive sooty mold, we will have to wait until the dormant season (November) to prune it due to the danger of stinging insects.
Second, improve the soil around the plant this fall per soil test results.
Third, the tree can be sprayed with a combination of a Neem oil product, horticultural oil, and a natural product derived from the chrysanthemum plant to stop the spread of the scale. Our spray equipment can reach trees up to 20' high; above that please call an arborist. Note that we will wait to spray when we see small white crawlers emerge next spring - this is the early development stage of the scale pest. At their most vulnerable, the spray will then be effective on the crawler.
Our Plant Health Care Manager, Al Newman, already has this action on his scouting calendar for 2019 and will notify you about the timing of his spray route. We will use our 200 gallon power sprayer for this work.
may have formed on phlox, peony, lilac and dogwood, among other plants. This is not fatal to the plant, just temporarily disfiguring. I use signs of mildew as a cue card. It tells me that we need to amend the soil as a preventative and/or move the plant to a better position where air will circulate. All such work is best done this fall. Thinning the plant by dividing or removing selected stems outright is another good strategy to prevent mildew.
Mildew of Phlox
If caught early, we can also spray the plant with an organic fungicide. However, this product does not work well on leaves that are already predominately white. At this stage, we recommend cutting the plant down early and disposing of the infected leaves in the trash. For the dogwood tree, leaves may defoliate early, and if so, rake up promptly and dispose away from the site.
Success with Container Seeds
I've had a lot of fun this summer with container vegetables. Since I ran out of space in the ground that receives more than 6 hours of sun many years ago, I constantly search out varieties that will thrive in my collection of pots. I can rotate the containers into the sun as needed, another plus. This spring I discovered that Renee's Garden has an extensive line of vegetable, herb and flower seeds bred to be just perfect for containers! Another trusted supplier is Fruition Seeds from upstate New York.
The mini basils have been particularly successful. Here is 'Piccolino' with very tiny leaves. I snip off the stalks with my sharp harvest scissors, then strip the leaves by hand. No chopping needed! Another great variety is 'Italian Cameo' with large leaves but a height less than 12." We started 'Piccolino' from seed indoors under lights. I scattered the seeds of 'Italian Cameo' directly in the pot sometime in June and soon was harvesting.
The dwarf nasturtium 'Elf' from Select Seeds has been charming both me and the hummingbirds. I keep its pot on my deck railing near the breakfast table to watch the action. The flowers are edible, too.
In spring I enjoyed Fruition's mesclun mix of lettuces and herbs called 'Salade de Provence' and used it cut-and-come-again style by snipping off the greens at the base. The plants quickly resprouted for a second and then a third round. Mesclun mix does best in cool weather.
Our excess kale and beet seedlings have been giving me multiple harvests of microgreens this way all summer. Next up will be Renee's dwarf bush bean 'French Mascotte' and cucumber 'Bush Slicer.' I'm pushing the envelope on these since I just remembered to put the seeds in the pots near the end of July. But with the warm falls we've had in the past few years...and my solar greenhouse...I just might get my harvest after all!